Alzheimer's compound repairs damaged neurons

“Amyloid accumulation occurs early in the disease, decades before memory loss, but very likely plays a causal role in initiating the disease,” said UC Los Angeles Alzheimer’s researcher Greg M. Cole. “So the best failed drugs targeting amyloid still need to be tested for prevention. Those trials are beginning. This record of failure is not true of drugs targeting tau pathology- the jury is still out.”

Cole said he agreed that boosting memantine’s effectiveness may provide some protection, but it’s unlikely to be effective against degeneration caused by the mutant tau protein. He is associate director of UCLA’s Mary Easton Alzheimer Center.

And UCSD neuroscientist Michael Rafii says evidence for the amyloid hypothesis includes a rare early-onset form of the disease which is characterized bv a mutation causing a buildup of amyloid beta plaques. The gene is autosomal dominant, so only one copy is needed to cause the disease.

"In addition, last summer there was a finding from an Iceland study by Decode Genetics that showed another kind of mutation that actually reduces the amount of beta amyloid produced, and those individuals do not develop Alzheimer's disease, even if they live for a very long time," Rafii said.